Effect of D-penicillamine in vitro and in vivo on macrophage phagocytosis.

Preincubation of rat peritoneal macrophages with D-penicillamine increased their uptake of labelled aggregated human gamma globulin ([125I]AHG)without affecting the rate of degradation of the aggregates. Administration of D-penicillamine (50 mg.kg?1. day?1 p.o.)to normal rats resulted in increased uptake of [25I]AHG by peritoneal macrophages after 4 days of treatment, but not after 14 and 28 days of treatment. In contrast, macrophages from rats with adjuvant arthritis treated with D-penicillamine (50 mg.kg?1. day?1 p.o.)exhibited an increased uptake of [125I]AHG throughout the course of the disease. Administration of D-penicillamine in vivo had no effect on the rate of degradation of [125I]AHG by freshly prepared macrophages. Culture for 24 hr in vitro prior to incubation with [125I]AHG led to a decrease in the rate of degradation of the labelled aggregates by macrophages from untreated or D-penicillamine-treated rats and from rats with adjuvant arthritis, but not by macrophages from D-penicillamine-treated adjuvant arthritic rats. It is suggested that D-penicillamine may exert a stimulatory effect on the reticuloendothelial function during chronic inflammatory disease, and that this effect may be mediated via an interaction with the macrophage plasma membrane.